1 files changed, 5 insertions, 1 deletions
diff --git a/jv.c b/jv.c
index b93854b3..bf7a0c51 100644
--- a/jv.c
+++ b/jv.c
@@ -230,9 +230,13 @@ static jv* jvp_array_read(jv a, int i) {
 }
 
 static jv* jvp_array_write(jv* a, int i) {
-  assert(i >= 0);
   jvp_array* array = jvp_array_ptr(*a);
 
+  if (i < 0)
+    i = array->length + i;
+  if (i < 0)
+    i = 0;
+
   int pos = i + jvp_array_offset(*a);
   if (pos < array->alloc_length && jvp_refcnt_unshared(a->u.ptr)) {
     // use existing array space